Dr. Andrew Thillainayagam said Gibb was being treated for advanced colorectal cancer and had caught pneumonia as he was weakened from grueling doses of chemotherapy and two operations.

The 62-year-old singer fell into a coma last week after contracting the pneumonia. Thillainayagam said that three days ago he had warned Gibb's family that he may not wake up. Instead, Gibb is now fully conscious and able to speak.

"It is testament to Robin's extraordinary courage, iron will and deep reserves of physical strength that he has overcome quite incredible odds to get where he is now," Thillainayagam said in a statement.